We have previously shown that non-thermal dielectric-barrier discharge (DBD) plasma induces the generation of reactive oxygen species (ROS) in cells; however, the underlying mechanism has not been elucidated. This study aimed to identify the mechanisms through which DBD plasma induces the expression of NADPH oxidase (NOX) family members by epigenetic modification in human keratinocytes (HaCaT). Cell exposure to DBD plasma in 10% oxygen and 90% argon resulted in the generation of ROS, triggering oxidative stress that manifested in various forms, including lipid membrane peroxidation, DNA base modification, and protein carbonylation. DBD plasma upregulated the expression of NOX1, NOX5, and DUOX2 at the mRNA and protein levels; and siRNAs targeting NOX1, NOX5, and DUOX2 attenuated the generation of DBD plasma-induced ROS. DBD plasma upregulated the transcriptional activators TET1, MLL1, and HAT1 and downregulated the transcriptional repressors DNMT1, EZH2, and HDAC1. Additionally, DBD plasma increased the binding of transcriptional activators and decreased the binding of transcriptional repressors to the DUOX2 promoter. Methyl-specific polymerase chain reaction and bisulfite sequencing indicated that DBD plasma decreased methylation at the DUOX2 promoter. These results suggest that DBD plasma induces ROS generation by enhancing the expression of the NOX system through epigenetic DNA and histone modifications.The well-documented anticarcinogenic properties of natural polyphenolic proanthocyanidins (OPC) have been primarily attributed to their antioxidant and anti-inflammatory potency. Emerging evidence suggests that OPC may target canonical oncogenic pathways, including PI3K/AKT; however, the underlying mechanism and therapeutic potential remain elusive. Here we identify that proanthocyanidin B2 (OPC-B2) directly binds and inhibits AKT activity and downstream signalling, thereby suppressing tumour cell proliferation and metabolism in vitro and in a xenograft and diethyl-nitrosamine (DEN)-induced hepatocellular carcinoma (HCC) mouse models. We further find that OPC-B2 binds to the catalytic and regulatory PH domains to lock the protein in a closed conformation, similar to the well-studied AKT allosteric inhibitor MK-2206. Molecular docking and dynamic simulation suggest that Lys297 and Arg86 are critical sites of OPC-B2 binding; mutation of Lys297 or Arg86 to alanine completely abolishes the antitumor effects of OPC-B2 but not MK-2206. Together, our study reveals that OPC-B2 is a novel allosteric AKT inhibitor with potent anti-tumour efficacy beyond its antioxidant and anti-inflammatory properties.Recent research suggests that melatonin (Mel), an endogenous hormone and natural supplement, possesses anti-proliferative effects and can sensitise cells to anti-cancer therapies. Although shikonin (SHK) also possesses potential anti-cancer properties, the poor solubility and severe systemic toxicity of this compound hinders its clinical usage. In this study, we combined Mel and SHK, a potentially promising chemotherapeutic drug combination, with the aim of reducing the toxicity of SHK and enhancing the overall anti-cancer effects. https://www.selleckchem.com/products/epz015666.html We demonstrate for the first time that Mel potentiates the cytotoxic effects of SHK on cancer cells by inducing oxidative stress via inhibition of the SIRT3/SOD2-AKT pathway. Particularly, Mel-SHK treatment induced oxidative stress, increased mitochondrial calcium accumulation and reduced the mitochondrial membrane potential in various cancer cells, leading to apoptosis. This drug combination also promoted endoplasmic reticulum (ER) stress, leading to AKT dephosphorylation. In HeLa cells, Mel-SHK treatment reduced SIRT3/SOD2 expression and SOD2 activity, while SIRT3 overexpression dramatically reduced Mel-SHK-induced oxidative stress, ER stress, mitochondrial dysfunction and apoptosis. Hence, we propose the combination of Mel and SHK as a novel candidate chemotherapeutic regimen that targets the SIRT3/SOD2-AKT pathway in cancer.Keratinocytes, the major cell type of the epidermis, are particularly sensitive to environmental factors including exposure to sunlight and chemical agents. Since oxidative stress may arise as a result of these factors, compounds are actively sought that can act as protective agents. Recently, cannabidiol (CBD), a phytocannabinoid found in Cannabis Sativa L., has gained increased interest due to its anti-inflammatory and antioxidant properties, and absence of psychoactive effects. This prompted us to analyze the protective effects of CBD on keratinocytes exposed to UVB irradiation and hydrogen peroxide. Here we show, using liquid chromatography mass spectrometry, that CBD was able to penetrate keratinocytes, and accumulated within the cellular membrane. CBD reduced redox balance shift, towards oxidative stress, caused by exposure UVB/hydrogen peroxide, estimated by superoxide anion radical generation and total antioxidant status and consequently lipid peroxidation level. CBD was found to protect keratinocytes by preventing changes in the composition of the cellular membrane, associated with UVB/hydrogen peroxide damages which included reduced polyunsaturated fatty acid levels, increased sialic acid and lipid peroxidation products (malondialdehyde and 8-isoprostanes) levels. This maintains cell membranes integrity and prevents the release of lactate dehydrogenase. In addition, CBD prevented UVB/hydrogen peroxide-induced reduction of keratinocyte size and zeta potential, and also decreased activity of ATP-binding cassette membrane transporters. Together, these findings suggest that CBD could be a potential protective agent for keratinocytes against the harmful effects of irradiation and chemical environmental factors that cause oxidative stress.Oxidative stress and inflammation in the brain are two key hallmarks of neurodegenerative diseases (NDs) such as Alzheimer's, Parkinson's, Huntington's and multiple sclerosis. The axis NRF2-BACH1 has anti-inflammatory and anti-oxidant properties that could be exploited pharmacologically to obtain neuroprotective effects. Activation of NRF2 or inhibition of BACH1 are, individually, promising therapeutic approaches for NDs. Compounds with dual activity as NRF2 activators and BACH1 inhibitors, could therefore potentially provide a more robust antioxidant and anti-inflammatory effects, with an overall better neuroprotective outcome. The phytocannabinoid cannabidiol (CBD) inhibits BACH1 but lacks significant NRF2 activating properties. Based on this scaffold, we have developed a novel CBD derivative that is highly effective at both inhibiting BACH1 and activating NRF2. This new CBD derivative provides neuroprotection in cell models of relevance to Huntington's disease, setting the basis for further developments in vivo.